THE HALDANE GAS-ANALYSIS APPARATUS 



115 



it is transferred into the caustic solution to free it from CO2, 

 and returned to the burette to determine the loss of volume due 

 to CC>2 absorption. It is then transferred into the alkaline pyro- 

 gallate solution, which frees it from oxygen, after which it is again 

 brought back to the burette to determine the loss in volume due 

 to the absorption of the 

 oxygen. 



The Apparatus. The 

 detail of the Haldane ap- 

 paratus is shown in the 

 accompanying cut. The 

 measuring burette 1 

 holds 21 c.c. The bulb 

 is of 15 c.c. capacity, 

 and the graduated stem, 

 which is about 4 mm. in 

 bore and 60 cm. in length, 

 is graduated to 0.01 c.c. 

 from 15 c.c. to 21 c.o. 

 The stopcock at the top 

 of the burette is double- 

 bored, so that in one 

 position air can be drawn 

 in from a gas sampler 2 

 and in another sent into 

 the absorption bulbs 3. 

 The lower part of the 

 burette extends through 

 the rubber cork at the 

 bottom of the water 

 jacket 4. A piece of 

 rubber tubing is at- -^ IG - ^- Haldane Gas Apparatus. (Macleod.) 

 tached to the bottom 



of the burette and is passed through a metal tube, furnished 

 on its inside with a metal disk which presses against the rubber 

 tubing, the pressure being controlled by means of a fine 

 adjusting screw 6. Below this a glass stopcock 7 connects with 

 rubber tubing to the mercury leveling bulb 5. The absorp- 

 tion bulb for CO2, containing 20 per cent NaOH or KOH 9, 

 is put in connection with the burette by suitably turning 



